13.3 Filament sensor
The new mechanical IR based sensor is more reliable than the optical filament sensor in the
previous version Original Prusa i3 MK3. The filament sensor can detect running out of
filament and is used for filament AutoLoad.
13.3.1 Running out of filament
Running out of filament
will no longer cause a print failure
. If you run out of filament, the
printer will automatically pause the print, unload the remaining few centimeters in the
heatbreak, and move the X-carriage away from the print. You will be prompted to replace the
spool and insert a new filament. Use pliers to remove the filament extruded during the
loading process. After that, you can continue in the
current print
.
13.3.2 False sensor readings and debugging
You can encounter false runout readings reported by the sensor. First step is to check if the
filament sensor is working properly in
LCD menu - Support - Sensor info
. When you
insert
filament
into the extruder, the IR state should be “
1
”. When you
unload and remove
the
filament from extruder, the state should change to “
0
”.
Possible causes might be:
13.3.2.1 Wiring problem
If the sensor is not changing state, please check whether the connectors are properly seated
on both sides of the sensor cable (extruder and Einsy side). In case of incorrect wiring, you
will see the IR sensor state as “0” (even when you insert a filament string).
Pict. 38 - Properly connected and seated filament sensor
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